This invention relates generally to the release of relatively high, locked loads, and more particularly concerns apparatus to suddenly release a high level dynamic or static load without damage to the locking member.
Prior load locking devices capable of sudden release have typically employed a locking ring contained in a relatively movable member that engages a groove or inclined surface in a relatively stationary member. A ram or piston is usually inserted into one of these members to force the lock ring into the groove, or against the inclined surface, and to unlock the movable member the ram is axially displaced. Under a high load at release, the locking ring must move radially to free itself from the groove or receptacle before the area of the lock interface can approach zero, and in single element locks this necessary radial acceleration cannot be achieved, which consequently results in high wear damage or failure of the locking member.
U.S. Pat. No. 3,813,065 discloses the use of a one-piece, split, chamfered and notched locking ring as a locking member between the load carrying members; and in that device the application of predetermined loads to the load carrying members releases the locking ring by flexure of the ring. In practice, problems and disadvantages can and do arise with the device of that patent. Such problems include the necessity that the ring flex, which increases the wear facter due to inadequate hardening; the ring can take a permanent set in use which produces a problem with adequate locking; and an out-of-round condition of the ring leads to difficulty with adequate ring collapse. Further, the chamfered and notched ring is difficult to produce, and the overall structure is found to be less than desirably rugged.